1. Field of the Invention
The invention relates to a heatable pipette tube with a controlled electric heater.
2. Descrition of the Related Art
A heatable pipette tube, such as the one described in Germ patent specification 26 26 332, permits regulatable heating extending over the pipette tube, with the exception of the tip end. A drawback of this design is that temperature control of samples is difficult. For example, if the heating and the regulation (control) is adjusted in order to temper larger volumes, there i a danger that smaller volumes may become overheted. Likewise, if the pipette is adjusted for small volumes, large samples may not become heated enough. There also exists a controllable heater for a centrifuge, into which a pipette tube may be inserted. However, temperature control with this arrangement is also problematic. That is, it is difficult to temper different volumes of pipette fluid quickly to a desired temperature without overheating the fluid.
EP-0 192 957 B1 describes an analysis device with a slide which transports via a pipette, fluid samples from a rotating plate to a tempered cuvette. The slide is provided with a controllable heater. This temperature controller pretempers the sample fluid to the temperature of the cuvette.
German Offenlegungsschrift 38 38 626 discloses a pipette tub hat is heated by electrically heated water. However, this heater lacks sufficient responsiveness because the water supply together with other structural parts must first be heated by the water to the desired temperature.